1. Field of the Invention
The invention relates to improvements in the mechanical structure of the spindle which rotates Winchester discs and in the actuator for the arms which carry the read-write heads.
2. Description of the Prior Art
Winchester disc drives have been used in the computer industry for many years. The discs have been rotated by a spindle driven by a spindle motor. In most instances, the motor driving the spindle shaft has been located below the shaft, increasing the height of the assembly. In at least one instance, the motor has been incorporated in the spindle hub, but in such a way that the shaft rotates in bearings inside a boss fixed to, or fastened to, the base. This necessitated small bearings between the shaft and the boss. The present invention is an improvement on motor-in-spindle hub construction in that the field coils and magnets are reduced in diameter and relatively large bearings are provided improving the strength of the structure and permitting more discs to be stacked on a spindle of given height.
The heads have been mounted on arms either of a linear movement type or a pivotal movement type, the latter being the field of the present invention. The actuator which moves the head mounting arm has in the past had a coil having its major axis perpendicular to the axis of the pivot. This has considerably increased the overall length of the actuator and decreased the mass of copper which has been incorporated in the structure, correspondingly reducing the motor force.